1. Field of the Invention
This invention relates to RF (radio frequency) shields, and more particularly, to such RF shields as are oftentimes incorporated in electrical apparatus employed in the communications industry.
2. Description of the Related Art
RF shields are frequently used to reduce interference and cross-talk in amplifier apparatus, such as might be found inside a cell site of a cellular communication system. In fact, several such shields may often be employed between adjacent circuits and systems to effectively compartmentalize the apparatus into separate operating units. The electrical apparatus is typically arranged with a printed circuit board and its electrical components positioned in a bottom section of a housing. An overlying cover section includes one or more of these RF shields as internal walls extending downwardly from the underside of the cover to separate the printed circuit board components into individual compartments. Once the wall alignment is in place, appropriate RF gaskets are glued to the bottom edges of these walls, or clipped to them (as with a bead of computer-fed plastic polymer material). The overlying cover is then screwed or clamped-down to the printed circuit board in conventional manner.
While such RF shielding, and the electrical apparatus which operates with such shielding in place, performs adequately well, the overall set-up process has been analyzed to be time consuming and labor-intensive. For example, common fabrication follows the taking of a block of aluminum, and machining it to make a prototype of the cover section with the number of divider walls required, then testing it. Even if no modifications are needed to the design, the usual next step is to proceed to a plaster casting--which could still be changed relatively easily and inexpensively if further testing shows that modifications are desirable. Once a design proves out electrically, the next step is to proceed to a die cast operation. Then, after final testing and approval, a mold is made,--which comprises a substantial portion of the cost of the part itself. If all has gone well, the RF gaskets are glued or otherwise secured to the bottom of each divider wall, before the cast cover section is screwed down, or clamped to the bottom section. Experience has shown that this process, even where all goes well, can take upwards of 15 weeks or more to complete.